A wide variety of construction machines are used to perform digging and digging-related tasks such as trenching, material spreading, grading, etc. An excavating machine is one such device, and a conventional design employs a multi-part linkage coupled with a bucket for capturing and moving material during a digging cycle. Each of the linkage components and the bucket will typically have one or more actuators coupled therewith. Each of the actuators, or actuator groups, may be coupled with separate control levers or other input devices. When it is desirable to dig a trench, for example, an operator is tasked with independently controlling a plurality of parameters. For operations which are relatively lengthy, complex and/or repetitive, the operator may experience significant fatigue from operating the various controls repetitiously. Moreover, operating efficiency in a work cycle may be less than optimal given the inherent limitations of human coordination, concentration and stamina.
In an attempt to relieve operators of certain of the stresses of long term, repetitive machine control, and to improve efficiency, engineers have developed a variety of automated work cycle control systems and processes over the years. One conventional approach for automating a work cycle in an excavating machine utilizes force feedback and position data associated with the linkage and bucket components as a basis for generating actuator control commands to move the linkage and bucket. In general terms, such a system relies upon sensor inputs indicative of force experienced by the linkage and bucket components during interacting with a material such as soil, sand, gravel, etc.
Such force-based systems have performed relatively well in the past, however, they are not without limitations. In particular, excavating machines may be required to perform automated digging cycles in a variety of different material types. Each material type has varying characteristics, such as strength, mass, frictional interaction with the bucket, etc. For example, a relatively hard, clayey soil will tend to have significantly different force interaction characteristics with the bucket of an excavating machine than a relatively looser and softer material such as dry sand. This variance in material characteristics across material types necessitates relatively extensive tuning and/or adjustment of an excavating machine and its associated automated digging cycle control system. In other words, no practicable one-size-fits-all approach has been developed, with the result that conventional digging cycle control systems are often programmed via a plurality of different maps which correspond to a plurality of different material types, often following extensive field testing and tuning. It is thus desirable to develop a system that can be used in a variety of different material types without the extensive data collection and programming required with conventional systems.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.